1. Field of the Invention
The present invention relates to a method for setting a steel stock discharge temperature of a heating furnace in a hot rolling line. Particularly, it is concerned with a steel stock discharge temperature setting method capable of attaining energy saving throughout the entirety of a hot rolling line including a heating furnace portion and a rolling portion.
2. Description of the Prior Art
Heretofore, in connection with the energy saving of a rolling line, reference has not been made to determining a steel stock discharge temperature itself, and it has been considered that a host computer is given such steel stock discharge temperature.
For example, as described in Japanese Patent Laid-Open Publication No. 133408/79, there is performed setting of a furnace temperature pattern for minimizing, in a heating furnace alone, the energy consumed in the heating furnace. And the steel stock discharge temperature is determined as follows. A metallurgically defined discharge temperature T.sub.out * and a discharge temperature T.sub.out ** to ensure the temperature at each point of a rolling line are tabulated experientially and the larger one is defined as the discharge temperature.
Generally, the discharge temperature T.sub.out ** defined from the rolling line is higher than the metallurgically defined discharge temperature T.sub.out *. Actually, however, the discharge temperature T.sub.out ** defined from the rolling line is determined experientially with a considerable margin, so there is a considerable waste from the standpoint of energy saving.
On the other hand, with respect to a rolling line, the discharge temperature is considered to be predetermined, and by a schedule calculation there are determined a plate thickness pattern and a speed pattern at each stand so as to satisfy restrictive conditions of the stand. Thus, the energy saving is not considered.
According to the conventional energy saving method in a rolling line, the energy in a heating furnace is minimized, assuming that the steel stock discharge temperature is predetermined. Thus, no consideration is given to the saving of energy throughout the entire line and consequently there is the drawback that energy is consumed wastefully.